package org.webslinger.ext.image;

 import java.awt.Rectangle;

 import java.io.File;

 import java.io.IOException;

 import java.util.ArrayList;

 import java.util.List;

 import java.util.ListIterator;

 import java.util.concurrent.CopyOnWriteArrayList;

 import org.apache.commons.collections.Transformer;

 import org.apache.commons.vfs.FileObject;

 import org.webslinger.util.TTLObject;

 import org.webslinger.io.IOUtil;

 public class ImageConvertor implements Transformer {

     protected final FileObject root;

     protected final String forceType;

     protected final List<ImageTransformerFactory> factories = new CopyOnWriteArrayList<ImageTransformerFactory>();

     protected String key;

     public ImageConvertor(FileObject root) {

         this(root, null);

     }

     public ImageConvertor(FileObject root, String forceType) {

         this.root = root;

         this.forceType = forceType;

     }

     public List<ImageTransformerFactory> getFactories() {

         return factories;

     }

     public Object transform(Object key) {

         return load((ImageDescriptor) key);

     }

     public TTLObject<FileObject> load(final ImageDescriptor image) {

         return new TTLObject<FileObject>() {

             protected String name;

             public long getTTL() {

                 return 1000;

             }

             protected FileObject load(FileObject dest) throws IOException {

                 FileObject source = image.getFile();

                 if (!source.exists()) {

                     if (dest != null) dest.delete();

                     return null;

                 }

                 ListIterator<ImageTransformerFactory> it = factories.listIterator();

                 int i = 0;

                 while (it.hasNext()) {

                     i++;

                     if (it.next().isEnabled(image)) {

                         while (i > 0) {

                             it.previous();

                             i--;

                         }

                         ArrayList<ImageTransformer> transformers = new ArrayList<ImageTransformer>();

                         StringBuilder newNameBuffer = new StringBuilder();

                         while (it.hasNext()) {

                             i++;

                             ImageTransformerFactory factory = it.next();

                             ImageTransformer transformer = factory.getTransformer(image);

                             if (newNameBuffer.length() > 0) newNameBuffer.append(';');

                             newNameBuffer.append(transformer.toString());

                             transformers.add(transformer);

                         }

                         while (i > 0) {

                             i--;

                             it.previous();

                         }

                         String newName = newNameBuffer.toString();

                         if (dest == null || !dest.exists()) {

                             return generate(source, newName, transformers.listIterator());

                         } else if (source.getContent().getLastModifiedTime() != dest.getContent().getLastModifiedTime()) {

                             return generate(source, newName, transformers.listIterator());

                         } else if (!newName.equals(this.name)) {

                             return generate(source, newName, transformers.listIterator());

                         }

                         return dest;

                     }

                 }

                 name = null;

                 if (dest != null && dest != source && !dest.equals(source)) dest.delete();

                 return source;

             }

             protected FileObject generate(FileObject source, String newName, ListIterator<ImageTransformer> it) throws IOException {

                 File tmpFile = File.createTempFile("image-convert", ".tmp");

                 tmpFile.deleteOnExit();

                 try {

                     IOUtil.copy(source.getContent().getInputStream(), true, tmpFile);

                     if (forceType != null) ImageUtils.convertType(tmpFile, forceType);

                     Rectangle dimensions = ImageUtils.getImageBox(tmpFile);

                     if (dimensions == null) return null;

                     while (it.hasNext()) {

                         ImageTransformer transformer = it.next();

                         if (!transformer.isEnabled()) continue;

                         dimensions = transformer.transform(tmpFile, dimensions);

                     }

                     FileObject dest = root.resolveFile(newName + '/' + source.getName().toString().replaceAll("_", "__").replaceAll(":", "_+").replaceAll("!", "_-"));

                     IOUtil.copy(tmpFile, dest.getContent().getOutputStream(), true);

                     dest.getContent().setLastModifiedTime(source.getContent().getLastModifiedTime());

                     name = newName;

                     return dest;

                 } catch (InterruptedException e) {

                     throw (IOException) new IOException(e.getMessage()).initCause(e);

                 } finally {

                     tmpFile.delete();

                 }

             }

         };

     }

 }